﻿/*******************************************************************************************
 * Copyright (c) 2006-2009 Alex Robson, Rob Simmons, Craig Israel, and Rachel Twyford
 *
 * Use of this software in any form requires that you have both 
 * read and agreed to the following terms:
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the "Software"), 
 * to deal in the Software without restriction, including without limitation 
 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions: 
 *
 * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 * Redistributions in binary form must reproduce the above copyright notice, 
 * this list of conditions and the following disclaimer in the 
 * documentation and/or other materials provided with the distribution.
 * Neither the name of Nvigorate nor the names of its contributors may 
 * be used to endorse or promote products derived from this software without 
 * specific prior written permission. 
 *
 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
 * DISCLAIMED. IN NO EVENT SHALL ANY CONTRIBUTOR BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * ****************************************************************************************/

using System;
using System.Collections.Generic;
using System.Data;
using Nvigorate.Common;
using System.Linq;
using Nvigorate.Relational.Mapping.Interface;

namespace Nvigorate.Relational.Record
{
    public class DataRowRecord : IRecord
    {
        #region Private Fields
        private int _fieldCount;
        private List<string> _fieldNames = new List<string>();
        private DataRow _row;
        private List<Type> _fieldTypes = new List<Type>();

        #endregion

        #region IRecord Members

        /// <summary>
        /// Returns the value for the field
        /// </summary>
        /// <param name="fieldName">Name of the desired field value</param>
        /// <returns>Object</returns>
        public object this[string fieldName]
        {
            get { return _row[fieldName]; }
            set { _row[fieldName] = value;}
        }

        /// <summary>
        /// Returns the value for the field
        /// </summary>
        /// <param name="fieldIndex">Name of the desired field value</param>
        /// <returns>Object</returns>
        public object this[int fieldIndex]
        {
            get { return _row[fieldIndex]; }
            set { _row[fieldIndex] = value; }
        }

        /// <summary>
        /// Returns the value for the field
        /// </summary>
        /// <param name="point">The assignment point which describes how to get the value from the record</param>
        /// <returns>object</returns>
        public object this[IAssignmentPoint point]
        {
            get
            {
                return _row[point.Field];
                return _fieldNames.Any(f => f.ToUpper().Equals(point.Field.ToUpper()))
                           ? _row[point.Field]
                           : _row[string.Format("{0}.{1}", RecordSource, point.Field)];
            }
            set 
            { 
                if(_fieldNames.Contains(point.Field))
                {
                    _row[point.Field] =  value;
                }
                else
                {
                    _row[string.Format("{0}.{1}", RecordSource, point.Field)] = value;
                }
            }
        }

        /// <summary>
        /// Number of fields in this record 
        /// </summary>
        public int FieldCount
        {
            get { return _fieldCount; }
        }

        /// <summary>
        /// List of field names in this record
        /// </summary>
        public List<string> FieldNames
        {
            get { return _fieldNames; }
        }

        /// <summary>
        /// Array of field values in this record
        /// </summary>
        public object[] FieldValues
        {
            get { return _row.ItemArray; }
        }


        /// <summary>
        /// The name of the source for this record
        /// </summary>
        public string RecordSource
        {
            get { return _row.Table.TableName; }
        }

        /// <summary>
        /// Returns the list of sources which contributed data.
        /// This is crucial to the update code.
        /// </summary>
        /// <param name="map"></param>
        /// <returns></returns>
        public List<string> GetContributingSources(IBindingMap map)
        {
            return map
                .Sources
                .Values
                .SelectMany(s => s.Assignments)
                .Where(a => HasFieldForAssignment(a.Source) && this[a.Source] != DBNull.Value)
                .Select(a => a.Source.Entity)
                .Distinct()
                .ToList();
        }

        /// <summary>
        /// Returns the type of the given field name
        /// </summary>
        /// <param name="fieldName">Field name</param>
        /// <returns>Type</returns>
        public Type GetFieldType(string fieldName)
        {
            return _fieldTypes[_fieldNames.IndexOf(fieldName)];
        }

        /// <summary>
        /// Returns the type of the field at the given index
        /// </summary>
        /// <param name="fieldIndex"></param>
        /// <returns></returns>
        public Type GetFieldType(int fieldIndex)
        {
            return _fieldTypes[fieldIndex];
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="point"></param>
        /// <returns></returns>
        public object GetValueForAssignment(IAssignmentPoint point)
        {
            return this[point];
        }

        /// <summary>
        /// Returns all related records by relationship name
        /// </summary>
        /// <returns></returns>
        public List<IRecord> GetRelatedRecords(string relationship)
        {
            return DataRowRecord.GetRecordsFromRows(_row.GetChildRows(relationship));
        }

        /// <summary>
        /// Returns an empty record which represents the schema
        /// of the related record
        /// </summary>
        /// <param name="relationship"></param>
        /// <returns></returns>
        public IRecord GetRelatedSchemaRecord(string relationship)
        {
            if (_row == null || _row.Table.DataSet == null)
                return new DataRowRecord();

            var relation = _row.Table.DataSet.Relations[relationship];
            
            if (relation == null)
                return new DataRowRecord();

            return new DataRowRecord(relation.ChildTable.NewRow());
        }

        #endregion

        public static implicit operator DataRowRecord(DataRow row)
        {
            return new DataRowRecord(row);
        }

        #region Public Methods
        public static List<IRecord> GetRecordsFromRows(DataRow[] rows)
        {
            List<IRecord> list = new List<IRecord>(rows.Length);
            foreach (DataRow row in rows)
            {
                list.Add(new DataRowRecord(row));
            }
            return list;
        }

        #region Implementation of IRecord

        public bool HasFieldForAssignment(IAssignmentPoint point)
        {
            return _row.Table.Columns.Contains(point.Field);
            return _fieldNames.Contains(point.Field) ||
                   _fieldNames.Any(f => f.ToUpper().Equals(string.Format("{0}.{1}", RecordSource, point.Field).ToUpper()));
        }

        #endregion

        #endregion

        #region Constructors
        public DataRowRecord()
        {
        }

        public DataRowRecord(DataRow row)
        {
            _row = row;
            _fieldCount = row.ItemArray.Length;
            foreach (DataColumn column in row.Table.Columns)
            {
                _fieldNames.Add(column.ColumnName);
                _fieldTypes.Add(column.DataType);
            }
        }
        #endregion

        #region Implementation of IDisposable

        /// <summary>
        /// Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.
        /// </summary>
        /// <filterpriority>2</filterpriority>
        public void Dispose()
        {
            _fieldNames.Clear();
            _fieldNames = null;
            _fieldTypes.Clear();
            _fieldTypes = null;
            _row = null;
        }

        #endregion

        public override int GetHashCode()
        {
            unchecked
            {
                var i = (FieldValues != null ? DelimitedBuilder.Construct(FieldValues.Select(v => v.ToString()), "|").GetHashCode() : 0);
                return i;
            }
        }

        public override bool Equals(object obj)
        {
            var values1 = this.FieldValues;
            var values2 = (obj as IRecord).FieldValues;

            return values1.SequenceEqual(values2);
        }
    }
}